The invention generally relates to forming a metal-to-metal seal in a well.
Polymer seals, which include rubber and plastic seals, are commonly used in downhole tools. Polymer seals are often used due to their flexibility, resilience and their ability to seal uneven or irregular surfaces. However, for some downhole environments, such as environments that present extremely high or low temperatures or corrosive fluids (as examples), conventional polymer materials may not be suitable. Furthermore, even in applications in which polymer seals may be used, material degradation, failure and property variations due to environmental changes may make the use of polymer seals challenging. A backup system typically is used with a polymer seal due to the seal's poor anti-extrusion resistance.
A metal seal may be used in a downhole application in place of a polymer seal. Metal seals generally exhibit superior stable mechanical and physical properties, as compared to polymer seals. However, seal design typically is more challenging for metal seals because the sealing mechanism is different from that of polymer seals. For example, a metal seal typically requires significantly more surface finishing and significantly more contact stress on the sealing surface.